1. Field of the Invention
The invention relates to ergonomic keyboards for computers and terminals.
2. Prior Art
In an effort to minimize repetitive strain injuries (RSI) such as carpal tunnel syndrome, keyboard manufacturers have turned their attention to ergonomic keyboards. Several approaches have been used.
One approach involves arranging the keys along a flat V or U shape instead of a straight horizontal line. The keys are arranged either in one continuous group along this shape, or in two groups. The advantage is that the angle of the user's arms is more natural and therefore more relaxed. Sometimes the keyboard also has a wrist rest. For example, see Camacho (U.S. Pat. No. 6,467,979 and others).
Another approach involves the use of the Dvorak key layout (ANSI standard X3.207) instead of the more common QWERTY key layout. The advantage is that the most commonly used keys are located on the home row, which minimizes finger travel and extension. For example, see Zagnoev (U.S. Pat. No. 5,936,555).
Another approach involves placing the keys below the level of the user's palm, or tilted downwards away from the user. This is instead of the usual arrangement where the keyboard is either tilted upwards away from the user, or it is flat on the desk. The advantage is that the user's palm slopes downwards along the surface of the keys, so it continues along the line formed by the user's arm from the shoulder downwards. Therefore the user's palm is more relaxed. For example, see Hargreaves (U.S. Pat. No. 6,005,496 and others).
All these approaches are beneficial. Some of the prior art combines a number of approaches to improve the keyboard. It would be best to combine all of these approaches.